Improvement in health-lifts



F. G. JOHNSON. HEALTHLIFT.

5 Na. 183,763. xmennea ot.31.1e7e.

THE GRAPHIC COMM PATENT FRANK G. -JOHNSON, OF NEW YORK, N. Y.

IMPRovEMENT IN HEALTH-LIFTS.

Specification forming part of Letters Patent No. l 873,763, datedOctober 31, 1876 application tiled April 17, 1876.

To all whom yt may concern:

Be it known'that I, FRANK G. JoHNsoN, of the city, county, and State ofNew York, have invented a new and useful Improvement in the Constructionof Health-Lifts; and I do hereby declare that the following is a full,clear, and exact description of the construe tion and operation of thesame, reference being had to the accompanying drawings, making a part ofthis specification, in which- Figure l represents a vertical section,Fig. 2 a plan view, partly in section, and Fig. 3 an enlarged view, o fa portion of Fig. 1.

The nature of my invention consists in arranging compound levers in sucha manner that within a small compass a light Weight of a few pounds willbalance or resist a heavy weight, and so arranging the light weight uponone of the levers that it may be shifted so as to indicate the amountthat may be desired to be lifted, from one to a thousand or more pounds.

The construction and operation of my machine are more fully described asfollows:

P represents a platform suitably elevated, and supported by legs R R,Fig. 1, to make room below the platform to arrange the levers Gr G andshaft C. Gr is a lever having its fulcrum at I, its short arm from I toH, and

its long arm from I to F. The face of the movable end of this lever at Fis a portion of a. circle, the center of which is the fulcrum I. Thereare two of these levers. D is a short lever, the fulcrum of which is thecenter of the shaft O. The end of this lever D forms a portion of acircle, the center of which is the center of the shaft C. The shaft Gextends from one side to the other of the platform, and projects beyondthe platform at one end. Upon this projecting portion of the shaft isfastened the long lever or scale-beam A. There are two of the shortlevers D. Upon the scalebeam A is placed a sliding weight, B, which issecurely held in any given position by means of the thumb set-screw d.The upper face of the scale-beam A is divided into spaces by figures,lines, and dots, to indicate where the weight B is to be placed toindicate the weight to be lifted. The lift is taken from the point H onthe lever G by means of the rod T, passing through the platform, andbeing furnished with suitable handles. E is a thin tlat flexible stripof metal, extending between the circular face or end of the long arm ofthe lever G and the circular face or end of the lever D. The upper endof this flat flexible strip of metal is securely fastened to the top ofthe circular face of the long arm F of lever` Gr, and the lower end isfastened to the bottom of the circular face of the lever D. The spacebetween the arms D and F is only sufficient to admit of the thinflexible strip of metal without friction. By means of the circular endsor faces of Ithe arms F and D, the length of these arms is not varied bytheir motion, or by any change in their height, and a vertical actionbetween them is always maintained. By uniting them with the exible stripof metal E obstructing friction is obviated.

In order to take a light lift on the machine without employing a weighttoo light for heavy lifting, l extend the scale-beam A back beyond itsfulcrum, as shown by a, and slot the weight B, as shown at b, by meansot which the weight can pass beyond the shaft C sufficiently to throwthe center of gravity of the weight at the fulcrum C or upon the backextension a, by which the weight is made to balance itself, or even toassist in lifting the levers A and G, if they should be too heavy fortaking the lightest desirable lift.

By this construction of the weight and scalebeam, a lift of from one toa thousand or more pounds can be afforded on the same machine by thesame weight.

1n order to make use of the above-described arrangement of the weight,the shaft C must extend beyond its bearing, and necessarily requires tobe of considerable size, thereby l causing considerable friction. Toobviate this friction, and not diminish the strength of the extendedportion of the shaft which carries the scale-beam A, there is providedin the stronger portion of the shaft G a V-shaped indentation or slot,C', the bottom or angle of which is at the center of the diameter of theshaft. J is a steel V- shaped bearing or knifeedge, upon which works thebottom of the slot O. The V-shaped slot C is as much longer than theknifeedge J as is necessary to allow the needed rotating motion of theshaft C in raising the Weight B.

By this arrangement, and by making the extended portion of the shaftwhich carries the scale-beam A smaller lthan the hole which it passesthrough beyond the bearing C', the friction of this end of the shaft isquite obviated, as all the pressure of the fulorum comes on the steelknife-edge J'.

Having thus explained my invention, what I claim, and desire to secureby Letters Patent, is-

1. In a health-lift, the combination of the levers G G and D D, theiradjacent ends being curved, with the shaft C, scale-beam A, and weightB, substantially in the manner and for the purposes set forth.

bination with the scale-beam A a, as described,

and for the purposes set forth.

FRANK G. JOHNSON.

Witnesses:

R. KNOX, G. M. KENDALL.

